package com.ruben.simplescaffold.filter;

import cn.hutool.core.lang.Opt;
import com.alibaba.fastjson.JSON;
import com.ruben.simplescaffold.utils.ResponseWrapper;
import lombok.extern.slf4j.Slf4j;
import org.slf4j.Logger;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 日志记录过滤器
 * // @Component
 * // @WebFilter(filterName = "LogFilter", urlPatterns = "/**")
 *
 * @author <achao1441470436@gmail.com>
 * @since 2021/7/29 9:58
 */
@Slf4j
public class LogFilter implements Filter {

    /**
     * The <code>doFilter</code> method of the Filter is called by the container
     * each time a request/response pair is passed through the chain due to a
     * client request for a resource at the end of the chain. The FilterChain
     * passed in to this method allows the Filter to pass on the request and
     * response to the next entity in the chain.
     * <p>
     * A typical implementation of this method would follow the following
     * pattern:- <br>
     * 1. Examine the request<br>
     * 2. Optionally wrap the request object with a custom implementation to
     * filter content or headers for input filtering <br>
     * 3. Optionally wrap the response object with a custom implementation to
     * filter content or headers for output filtering <br>
     * 4. a) <strong>Either</strong> invoke the next entity in the chain using
     * the FilterChain object (<code>chain.doFilter()</code>), <br>
     * 4. b) <strong>or</strong> not pass on the request/response pair to the
     * next entity in the filter chain to block the request processing<br>
     * 5. Directly set headers on the response after invocation of the next
     * entity in the filter chain.
     *
     * @param request  The request to process
     * @param response The response associated with the request
     * @param chain    Provides access to the next filter in the chain for this
     *                 filter to pass the request and response to for further
     *                 processing
     * @throws IOException      if an I/O error occurs during this filter's
     *                          processing of the request
     * @throws ServletException if the processing fails for any other reason
     */
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        ResponseWrapper wrapper = new ResponseWrapper((HttpServletResponse) response);
        HttpServletRequest req = (HttpServletRequest) request;
        String uri = req.getRequestURI();
        long startTime = System.nanoTime();
        chain.doFilter(request, wrapper);
        // 获取response返回的内容并重新写入response
        String result = wrapper.getResponseData(response.getCharacterEncoding());
        response.getOutputStream().write(result.getBytes());

        Opt.of(log).filter(Logger::isInfoEnabled).ifPresent(l -> {
            log.info("method:{}", req.getMethod());
            log.info("uri:{}", uri);
            log.info("parameterMap:{}", JSON.toJSONString(req.getParameterMap()));
            log.info("responseCode:{}", wrapper.getStatus());
            log.info("result:{}", result);
            log.info("timeCost:{}", (System.nanoTime() - startTime) / (1000.0 * 1000.0) + "ms");
        });
    }


}
